The present invention relates to a heat developing apparatus by which a photothermographic element is heated and developed, and particularly to a countermeasure by which the image quality of the element conveyed, is not badly affected by the condensates from gas generated at the heat developing apparatus, and further, to the collection and recovery of the condensates from gas generated at the heat developing apparatus.
In the heat developing apparatus by which the photothermographic element is heat-developed, an exposed photothermographic element is nipped between a drum-like heat applying member (heat drum) which is temperature controlled to a predetermined heat developing temperature, and an urging member (opposite roller) opposite to this member, and the element is heated while the heat applying member is rotated in the held status. After that, the photothermographic element is separated from the heat applying member, cooled and the heat development is stopped, and the photothermographic element is conveyed to the delivery direction. The photothermographic element is heat developed through such the process.
As described above, in the heat developing apparatus, in order to obtain a desired developing density, the predetermined thermal energy is given to the photothermographic element for a predetermined time.
On the one hand, in the photothermographic element, the photosensitive silver halide, organic acid silver salt, binder, and other various additives or solvents are contained.
As repeating the developing processing, when the heat applying member (heat drum) or urging member (opposite roller) and photothermographic element are in contact with each other at the high temperature condition, the material contained in the photothermographic element or the organic acid isolated from the organic acid silver salt is transferred onto the heat drum or the opposite roller, vaporized or decomposed and after that, accumulated inside the heat developing section as condensates from gas, and thereby, the image defect or density lowering occurs. Accordingly, after the processing of a predetermined amount or a predetermined period of photothermographic element, the maintenance washing of the heat developing apparatus has been necessary.
Further, in order to increase the nipping and conveying performance under the high temperature, the elastic body is used for the surface of the heat drum or opposite roller in many cases, and in such the case, there are problems that the composition of the elastic body is deteriorated due to the deterioration by the heat or the material generated from the film, and the strength of the elastic body itself is lowered, further, when the organic solvent type cleaning agent is used for removing the accumulated foreign matter, the crack is generated on the elastic body itself, or the life of the elastic body itself is reduced.
The first object of the present invention is to minimize foreign matter such as the condensates from gas generated at a developing section, accumulated on a guide member particularly to guide the photothermographic element from upstream into the developing section, or to guide from the inside of the developing section to downstream.
The second object of the present invention is to minimize foreign matter such as the condensates from gas generated at a developing section accumulated on the surface of members inside the heat developing section and members on their periphery.
The first object is attained by any one of the following structures (1) to (12).
(1) A heat developing apparatus which is characterized in that in the heat developing apparatus having a heat applying member to conduct the heat developing by heating a photothermographic element in a developing station, and a guide member to guide the element to the developing section, or a guide member to guide the element from the developing section to the downstream portion in the developing station covered by a housing, at least either one of surfaces of the guide members is structured by a material having a low heat conductivity such as, for example, a heat insulating material.
(2) A heat developing apparatus according to (1), wherein an exhaust apparatus is connected to the developing section, and a suction air portion from the developing section is in the vicinity of an installation position of at least either one of the guide members.
(3) A heat developing apparatus according to any one of (1) or (2), wherein the guide members are exposed outside the developing section.
(4) A heat developing apparatus according to (3), wherein the heat conductivity of each of the guide members is not larger than 1 W/(mxc2x7K).
(5) A heat developing apparatus according to any one of (1) to (4), wherein the material of each of the guide members is a resin material or a rubber-like elastic body.
(6) A heat developing apparatus which is characterized in that: in the heat developing apparatus having a heat applying member to conduct the heat developing by heating a photothermographic element in a developing station, and a guide member to guide the element into the developing station, or a guide member to guide the element from the developing section to the downstream portion in the developing station covered by a housing, there is arranged a heat applying means for maintaining at least either the guide member to guide the element into the developing station, or the guide member to guide from the developing station to the downstream portion, at not lower than 80xc2x0 C.
(7) A heat developing apparatus which is characterized in that: in the heat developing apparatus having a heat applying member to conduct the heat developing by heating a photothermographic element in a developing station, and a guide member to guide the element into the developing station, or a guide member to guide from the developing station to the downstream portion in the developing station covered by a housing, there is arranged a heat applying means for maintaining the difference between the heat developing temperature and the temperature of at least either the guide member to guide the element into the developing station, or the guide member to guide the element from the developing station to the downstream portion, at not higher than 50xc2x0 C.
(8) A heat developing apparatus which is characterized in that: in the heat developing apparatus having a heat applying member to conduct the heat developing by heating a photothermographic element in a developing station, and a guide member to guide the element into the developing station, or a guide member to guide from the developing station to the downstream portion in the developing station covered by a housing, there is arranged that at least either the guide member to guide the element into the developing station, or the guide member to guide the element from the developing station to the downstream portion, does not directly face the heat applying member.
(9) A heat developing apparatus according to (6), wherein the shielding member is arranged so that the path of the element passing on the guide member does not directly face the heat applying member.
(10) A heat developing apparatus according to (9), wherein the shielding member is arranged from the leading edge portion of the guide member in the conveying direction to the downstream of the guide member in the conveying quad direction.
(11) A heat developing apparatus according to any one of (8), (9) or (10), wherein the shielding member serves also as the guide member.
(12) A heat developing apparatus which is characterized in that: in the heat developing apparatus having a heat applying member to conduct the heat developing by convection heating a photothermographic element conveyed to a developing station, and a guide member to guide the element into the developing station, or a guide member to guide the element from the inside of the developing station to the downstream portion in the developing station covered by a housing, the outside air is taken in from the vicinity of the guide member so that the gas generated from the photothermographic element does not reach at least either the guide member to guide the element into the developing station, or the guide member to guide from the inside of the developing station to the downstream portion.
The second object is attained by any one of the following structures (13) to (22).
(13) A heat developing apparatus which is characterized in that: in the heat developing apparatus having a heat applying member to conduct the heat developing by convection heating a photothermographic element in the developing station covered by a housing, an accumulation member for solidifying or precipitating a gas is arranged in the housing.
(14) A heat developing apparatus according to (13), wherein the accumulation member is structured by the material having the high heat conductivity.
(15) A heat developing apparatus according to any one of (13) or (14), wherein the accumulation member is provided with a cooling structure or cooling apparatus for cooling the accumulation member.
(16) A heat developing apparatus according to (15), wherein the temperature of the accumulation member is made not higher than 80xc2x0 C. by the cooling structure or cooling apparatus.
(17) A heat developing apparatus according to (15), wherein the temperature of the accumulation is made lower than the heat developing temperature by not smaller than 40xc2x0 C. by using the cooling structure or cooling apparatus.
(18) A heat developing apparatus according to any one of (13)-(17), wherein the accumulation member is made detachable.
(19) A heat developing apparatus according to any one of (13)-(18), wherein the accumulation member is disposed on the lower side of the passing path of the photothermographic element.
(20) A heat developing apparatus according to any one of (13)-(18), wherein the accumulation member is on the upper side of the passing path of the photothermographic element, and is provided with a liquid dripping prevention means for preventing liquid collected on the accumulation member from dripping to the element.
(21) A heat developing apparatus according to any one of (13)-(18), wherein the accumulation member serves also as the guide member for guiding the photothermographic element.
(22) A heat developing method which is characterized in that: in the heat developing method by which the photothermographic element is nipped and conveyed at a predetermined speed by a heat applying means to apply the heat to a photothermographic element, and an urging means to urge the element to the heat applying means, and the photothermographic element is developed, an accumulation means of the condensates from gas is arranged in the inside of the heat developing section having the housing covering the heat applying means and urging means.